LONDON (Reuters) - Russian-based operatives placed three adverts on Facebook in the run-up to Britain’s 2016 referendum on EU membership, spending just 97 cents to raise the issue of immigration, the social media platform said on Wednesday.

People stand in front of a logo at Facebook's headquarters in London, Britain, December 4, 2017. REUTERS/Toby Melville

Some British lawmakers have called for an inquiry into whether Russia meddled in Britain’s vote to leave the EU after social media platforms said Russian operatives sought to interfere in the U.S. election of Donald Trump.

Russia denies meddling in Brexit or the U.S. election.

Facebook sent its findings to the Electoral Commission which is examining how digital campaigning is affecting politics in Britain, including activity funded from outside the country.

Facebook said it had examined whether any account profiles or pages linked to the Internet Research Agency (IRA) had funded ads during the Brexit vote. The IRA is a Russian organization that according to researchers employs hundreds of people to push pro-Kremlin content on social media.

“We have determined that these accounts associated with the IRA spent a small amount of money ($0.97) on advertisements that delivered to UK audiences during that time,” Facebook said.

“This amount resulted in three advertisements (each of which were also targeted to U.S. audiences and concerned immigration, not the EU referendum) delivering approximately 200 impressions to UK viewers over four days in May 2016.”

A separate cross-party British parliamentary committee is also investigating whether any Facebook ads were bought by Russian-linked accounts around the EU referendum and the 2017 UK election.

The issue of whether Russia intervened in the 2016 U.S. presidential election is the subject of multiple investigations.

Facebook said in October that Russia-based operatives published about 80,000 posts on the social network over a two-year period in an effort to sway U.S. politics and that about 126 million Americans may have seen the posts during that time.

The Electoral Commission, which oversees the running of British elections, said it would say more about its findings in due course.